The present invention relates generally to a communications system having pre-defined restricted user groups. More particularly, the present invention relates to a cellular telephone system wherein at least some group members within such a pre-defined group are restricted to making telephone calls to and receiving telephone calls from other group members only.
Many organizations have work forces spread out over a relatively wide geographic area. Such work forces and organizations may for example be: drivers for a hauling concern, an ambulance company, a courier company, or the like; work crew members for an electric, cable, or water utility or the like; salespersons for a sales company or the like; service technicians for a copier repair firm, computer repair firm, or the like; repair and maintenance technicians for a climate control service firm, a plumbing or electrical service firm, or the like; roving laborers for a contractor or the like; or security officers for a security firm, private security force, or the like, among others. In most if not all cases, the organizations would prefer to be in close communication with such work force workers.
Previously, such organizations could only maintain such close contact by building and operating their own private radio communications systems or by contracting with radio communications system service providers. As should be understood, such private systems are quite costly. With the advent of widely available cellular telephone service, however, many organizations have found it advantageous to provide at least some of their work force workers with cellular telephones (xe2x80x9ccell phonesxe2x80x9d). Accordingly, workers, dispatchers, supervisors, and other appropriate personnel can conveniently and easily contact one another, as the case may be. Moreover, such organizations need not expend the costs associated with maintaining or contracting for private radio communications systems.
As should be evident, with the provided cell phone, each worker can make calls to and receive calls from work-related individuals for work-related purposes. However, each worker may also use the provided cell phone to contact non-work-related individuals for non-work-related purposes. As should be understood, such non-work-related uses may prove to be quite costly and are at any rate considered undesirable. A need exists, then, for a cellular telephone system that prevents at least some workers from using provided cell phones for non-work-related uses.
In a preferred embodiment of the present invention, the aforementioned need is satisfied by a communications system having a pre-defined calling group with a plurality of members. In particular, in the present invention, a plurality of personal communication devices (PCDs) each have a system ID and a group ID, and each member of the group is assigned one of the PCDs. The system ID and the group ID both have a predetermined characteristic, where each system ID has a first variation with respect to the characteristic and each group ID has a second variation with respect to the characteristic. A first member of the group having a first PCD, then, attempts to contact a second member of the group having a second PCD by entering into the first PCD the group ID of the second PCD.
A communications switch allows the first PCD to access the communications system thereby. The first PCD transmits information to the communications switch, where the transmitted information includes the system ID of the first PCD and the group ID of the second PCD. A switch database is in communication with the communications switch, and includes a record for the first PCD. The record includes information that the first PCD is assigned to a member of the group. The communications switch locates the record for the first PCD based on the system ID of the first PCD, and determines based on the record for the first PCD that the first PCD is allowed to contact the second PCD by way of the group ID of the second PCD.
A group database is in switchable communication with the communications switch. The group database has the system ID and the group ID for the PCD of each member of the group. The communications switch forwards the attempted contact and the group ID of the second PCD to the group database for further processing. The group database determines that the group ID of the second PCD is located therein, locates the system ID of the second PCD based on the group ID of the second PCD, and forwards the attempted contact and the system ID of the second PCD to an appropriate communications switch for further processing.
In a preferred embodiment of the present invention, the calling group has a plurality of members including restricted members and non-restricted members. Each restricted member is restricted to contacting non-restricted members and other restricted members within the group. Each non-restricted member is able to contact restricted members, other non-restricted members, and non-group individuals. The record for the first PCD includes a first designator designating that the first PCD is assigned to a member of the group and a second designator indicating whether the first PCD is assigned to a restricted member or a non-restricted member.
If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a restricted member, the communications switch allows the attempted contact to proceed if the number of the communications device has the second variation. If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a non-restricted member, the communications switch allows the attempted contact to proceed if the number of the communications device has the first or the second variation. If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a non-restricted member and if the number of the communications device has the first variation, the communications switch forwards the attempted contact and the number of the communications device to an appropriate communications switch for further processing. If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a restricted member or a non-restricted member and if the number of the communications device has the second variation, the communications switch forwards the attempted contact and the number of the communications device to the group database for further processing.